In a major upsurge of violence, Israeli forces have killed at least nine Palestinians following the deaths of four Israelis a day earlier.
An Israeli helicopter gunship fired at least one missile at an office of the Islamic militant group Hamas in the Jabalya refugee camp in the Gaza Strip Tuesday, killing at least two people.
Earlier, Palestinian officials said three Palestinians were killed in Khan Yunis town, where Israeli tank fire destroyed several homes.
Israeli warplanes also bombed Palestinian security targets in the Gaza Strip, destroying a military intelligence building and a complex of the Palestinian Force-17 security unit in Rafah town.
Elsewhere in Gaza, Israeli troops shot and killed one Palestinian gunman trying to infiltrate a Jewish settlement. Another Palestinian was shot and killed in the same general area late Monday.
In the West Bank, Israeli F-16 fighter jets destroyed the Palestinian Authority police headquarters near the town of Ramallah.
Israeli troops also killed two armed Palestinians and wounded six others during a gunfight near the Batala refugee camp near the town of Nablus, also in the West Bank.
The Israeli military moves were in retaliation for the killing of four Israelis - one settler, one policeman and two soldiers - in separate attacks Monday.
The European Union says it is sending its foreign policy chief, Javier Solana, to the Middle East this week for more talks aimed at bringing peace to the region.